Aileron



E. F. ZAPARKA AILERON Aug. y28, 1934.

Filed July 2l, 1953 4 Sheets-Sheet l ug. 28, 1934. E. F. ZAPARKA1,971,591

AILERON Filed July 2l, 1955 4 Sheets-Sheet 2 Aug. 28, 1934.

E. F. zAPARKA 1,971,591

AILERON Filed July 21, 1933 4 Sheets-Sheet 3 Aug. 28; 1934.

E. F. ZAPARKA 1,971,591

AILERON Filed July 2l, 1953 4 Sheets-Sheet 4 fawn/eo /f-ZAPa/a/mPatented Aug. 28, 1934 PATENT OFFICE AILERON Edward F. Zaparka,Baltimore, Md., assignor to Zap Development Corporation, Baltimore, Md.,a corporation of Delaware Application July 21, 1933, Serial No. 681,642

37 Claims.

This invention relates to airplanes, and more particularly to means foreiecting lateral control of airplanes.

This application contains' subject matter and 8 claims common toapplicants co-pending application Serial No. 653,918.

An object of my invention is to provide means for lateral control, suchas aileron constructions which are simple in operation and will give a lvery sensitive and powerful lateral control of the plane.

Another object of my invention is to provide Such a construction inwhich the construction is sturdy, and in which there are few operatinglli parts and the repair and replacement are easily and cheaplyeffected.

With these and other objects in view, which may be incident to myimprovements, the invention consists in the parts and combinations to behereinafter set forth and claimed, with the understanding that theseveral necessary elements comprising my invention may be varied inconstruction, proportions and arrangement, without departing from thespirit and scope of the appended claims.

In order to make my invention more clearly understood, I have shown inthe accompanying drawings means for carrying the same into practicaleffect without limiting the improvements in their useful applications tothe particular constructions, which, for the purpose of explanation,have been made the subject of illustration.

In the drawings:

Figure 1 is a perspective view, part of the construction being lbrokenaway, showing -an embodiment of my invention and the control means foreffecting the positioning of the ailerons;

Fig. 2 is a diagrammatic top plan view of the operating mechanism, partsof the mechanism being broken away to save space;

Fig. 3 is a cross sectional view taken through a. wing showing onelocation of an aileron embodying my invention;

Fig. 4 is a cross sectional View taken through a wing showing anotherembodiment of my aileron;

Fig. 5 is a view similar to that shown in Fig. 4, showing a stillfurther embodiment of my aileron;

Fig. 6 is a view similar to that shown in Fig. 4, showing yet anotherembodiment of my aileron;

Fig. 'l is a view similar to that shown in Fig.

4, showing still another embodiment of my aileron; l

Fig. 8 is a perspective view of the detailed construction of the aileronitself, part of the cover of the aileron being removed to more clearlyindicate the position of the parts;

Fig. 9 is a detail perspective view showing operating mechanism for afloating aileron construction;

Fig. l() is a detail side elevational view of a Wing with a oatingaileron construction;

Fig. 11 is a view similar to Figure 10, showing another floating aileronlocation;

Fig. 12 is a view similar to Figure 10, showing another floating aileronlocation;

Fig. 13 is yet another view similar to Figure )1.0, showing stillanother floating aileron locaion;

Fig. 14 is yet another view similar to Figure 10 showing a differentfloating aileron location.

Referring to the drawings, in Fig. 1 I have shown an airplane havingwings 1, a fuselage 2, a motor 3 provided with a propeller 4, and anempennage structure comprising a rudder 5, stabilizer surfaces 6 andelevators 7. @0

The wings 1 are provided with ailerons 8 mounted on aileron supports 9,as seen in Figure 3. The ailerons 8 are provided with horns 11.

v The mounting of the aileron and its interior construction are plainlyapparent from an inspection of the view shown in Figure 8. Each aileron8 consists of a longitudinally positioned torque tube l2 over which aremounted transverse bracing members 13 so shaped as to give the aileron,when covered by a suitable fabric or other covering, the proper shape.

The transverse bracing elements 13 are joined to a rod 14 at theirtrailing edge and to another rod l5 at their leading edge. Thetransverse bracing members 13, located at the ends of the ailerons, arereinforced with a reinforcing structure 16. The torque tube 12 hasattached to it the horn 1l above mentioned, which is provided with aball 17 at its end adapted to cooperate with a socket joint located at18 in control rods 19, for operating the ailerons. Attached tothe.longitudinally disposed torque tubes 12 are spaced supports 21 in whichis journaled a pivot 22 carried by the aileron support 9. The positionof the parts can be seen in dotted lines in Figure 3.

Each operating rod 19 for each aileron is provided with a socket joint23 at its end which engages with a ball member 24 mounted on anoperating arm 25. The operating arm 25 is preferably integrally formedwith force transmitting arms 26 and 27. To the force transmitting arm 26is attached a cable 28, and to the force transmitting arm 27 is attacheda cable 29. The member comprising the operating arm 25 and the forcetransmitting arms 26 and 27 is pivotally mounted at 31 on a bracket 32attached to a forward wing spar 33.

The horn 11 is so positioned that for any given movement of theoperating rod 19 there is a greater movement of the trailing edge of theaileron in the up or raised position than there is for the trailing edgeof the corresponding opposite aileron into the down or lowered position,This type of movement is well known in the art and is not a novelfeature with the applicant.

The cable 28 connects the force transmitting arms 26 and the cable 29connects the force transmitting arms 27. 'I'he cable 29 passes overpulleys 34 and 35, and over other pulleys, not shown, located near thefloor of the cockpit, and thence the cable 29 passes over a drum 36which is adapted to be rotated by a hand wheel 37.

By rotating the hand wheel 37 vthrough the cables 29 and 28, theoperating arms 25 can be moved as indicated in dotted lines in Figure 2to cause the ailerons 8 to assume the desired positions. When theaileron on the right hand wing is moved into the down position, (withits trailing edge lowered) the aileron on the left hand wing is adaptedto be moved in the up position, (with its trailing edge raised) and asbefore stated, the movement of the trailing edge of the aileron into theup position will be greater than the movement of the trailing edge ofthe opposite aileron into the down position It will be noted that theailerons 8 are narrow but long and, therefore, aiect the flow of airover a substantial portion of the area of the upper surface of thewings. When an aileron is moved into the down position, at favorableangular setting, it aects the flow around the wing to tend to preventburbling or turbulence, and tends to hold the flow in contact with theupper surface of the wing. This has a noticeable effect in increasingthe lift coecient of the wing on which the aileron is moved in the downposition. By being moved into the down position, I mean, that thetrailing edge of the aileron is moved down. The lift coeflicient,therefore, is increased and we have not only the eiect of the aileronitself acting by vits airfoil section in the ow to .raise that Wing whenit is moved in its down position, but we have the additional effect ofthe aileron on the wing itself, -tending to increase the efficiency ofthe Wing as a lifting surface. 'This feature is of extreme importanceand gives a sensitivity and positiveness of4 control which is highlydesirable.

The effect is opposite upon the raising of an aileron, that is to sayraising the trailing edge of the aileron -tends to disturb the flowaround the wing, thus tending to lower the lift coeiicient of the wingupon Which the aileron is raised.

The ailerons thus give both positive and negative lift effect on thewings themselves, which is in addition to the positive and negative lifteffect which is achieved through the instrumentality of the aileronsacting by their airfoil sections in the ow.

Because of this unique effect of the aileron by reason of its locationand form, efciency and sensitivity of lateral control is greatlyincreased over prior practice.

In Figure 3 Ihave shown the aileron located so that its pivot point isapproximately h'alf an aileron chord distant from the upper surface ofthe wing, and so positioned laterally with respect to the trailing edgethat the nose of the aileron lies approximately about a half chordforward of the trailing edge of the wing. This location of the aileronis very ecient. There is a noticeable effect on the flow around the wingwhen the aileron is moved because the aileron is not too close tointerfere with this desirable action.

In Figure 4 I have shown the aileron positioned laterally approximatelythe same as in the form of aileron shown in Figure 3, but the aileron ismoved farther above the wing. In this instance the point of pivoting forthe aileron is approximately a full aileron chord above the uppersurface of the trailing edge of the wing.

In another form of my invention, such as in Figure 5, I have shown theaileron positioned laterally approximately as shown in Figures 3 and 4,but the pivot point of the aileron is moved approximately two aileronchords above the upper surface of the trailing edge of the wing.

In Figure 6 I have shown the aileron pivoted approximately half anaileron chord above the upper surface of the wing while the nose of theaileron is approximately two aileron chords forward of the trailing edgeof the wing.

In Figure rI I have shown the aileron pivoted approximately half a chordabove the trailing edge of the wing but so mounted that the nose of theaileron is approximately a full aileron chord to the rear of thetrailing edge of the wing.

The forms shown are the preferable forms of my invention. Preferably Ilocate the aileron from one third of a chord to two aileron chords abovethe trailing edge of the wing, and in such positions that the nose ofthe aileron shall be from two aileron chords in front of the trailingedge to one aileron chord in rear of the trailing edge of the wing.Another way of stating it is that the trailing edge of the aileron shallbe approximately one chord in front of the trailing edge of the wing ortwo chords to the rear of the trailing edge of the wing. I do not desireto be limited within the exact limits as indicated. In some forms ofconstruction the limits I propose may be used, or in some cases evenincreased, and in other forms of plane construction it is not desirableto have the aileron assume the positions indicated by the limitsmentioned. In general it is desirable to so locate the ailerons abovethe wings as to increase the ow of the combination of aileron and Wingon the side to be raised and to decrease the velocity of air flow overthe upper surface of the opposite side. This produces a desirablerotation about the fore and aft axis of the plane, which is the'productof the action of the ailerons themselves and of the effect of the airflow over the surfaces of the wings as modified by the aileron action.

While I have shown various positions of my aileron construction in thedrawings and given some denite limits for eciency of operation withrespect to the position of the ailerons, I wishA it to be distinctlyunderstood that I am not limited in. my broadest concept to theparticular showings made. I believe myself to be the first to discoverand put to practical application the use of ailerons which are distinctand separate from the major airfoil sections and which are not a part ofthe major aircil section in any sense, land which affect the flow arounda material poru basically, I believe myself to be the first to discoverthat an aileron which is in no sense.apart of the major airfoil can beused to affect the flow around the major airfoil both positively andnegatively to cause a sufficient change of the ow over a sufficient areaof the main airfoil to produce a practical and usable rolling momentwhich is, in addition, to the rolling moments produced by the airfoilsections of the ailerons per se.

Therefore, theapparent indecision on aileron location is not one ineffect and the phraseology of the above location definition is caused bythe manner of stating the location point by multiples of aileron chord.There is, however, an interrelation existing as to favorable aileronlocation as to wing, chord and aileron chord dimensions, and thelocation definitions given here are also taking care of that phenomenon.While we also term the location as specified by vdescription of Figure 3as a favorable one, the other locations are giving satisfactory results.The research which I have done is not limited to the positions ofaileron illustrated, and other aileron positions around the mainairfoil, such as in the vicinity of the forward part of the mainairfoil, have proven advantageous and to possess the inherent operativefeatures which I have here disclosed.

` In order to explain what I mean by the term downflow, as used in theclaims, it must be re-Y marked that the region of ow above a wing can bedivided into two parts, namely, the upflow and the downflow, relative tothe flight path of the airplane. The term downflow used in the claimsrefers to that region above the surface of the airfoil. in which theairflow is deflected downward from its original relative directionparallel to the line of flight of the aircraft or wing.

ft is the location of the ailerons substantially within the downflowover av wing which is of great -Vv,importance in achieving the desirablereactions which I have described. In some instances the aileron may belocated well forward of the for- Ward position dened in aileron chordswhich I have just set forth, but so long as the aileron liessubstantially within the downflow, the desirable results areobtained. f

The term downflow as used in the claims also is intended to cover thatflow of air which occurs back of and adjacent to the trailing edge ofthe wing. The .word downfiow therefore is intended to cover the flow ofair around an aileron located above the wing but substantially rear ofthe trailing edge. Such airflow back of the trailing edge of the wing isoften called downwash, but the word downflow as I here employ it coversthisdownwash area as well as the flow of air adjacent to and over theuppei` rear surface of the Wmg.

Referring to the drawings, I have shown a float:- ing aileron mechanismwhichis probably best shown in the perspective view, Figure 9. Thelocation of these floating ailerons in my invention is the same as forthe ordinary ailerons. There are certain inherent advantages in floatingailerons which are additional to the advantages of my v moments.

ordinary aileron construction. 'Ihe type of float-- ing aileronconstruction I have shown is one in which the ailerons float together..'I have found that this type of floating aileron construction in thelocation which I employ is somewhat preferable to a floating aileronconstruction in which each of the ailerons may float separately.l Wherethe ailerons float together there is more inherent stability in thecombination than. is the case The shafts 58 are suitably journaled onsupports 59 attached to the front wing spars. The ends of the shafts 58opposite the cranks 57 are provided with cranks 61 which carry ballmembers 62. The ball members 62 engage with socket members formed inenlarged portions 63 of rods 64.

The rods 64 at their lower ends carry socket members at 65 in which areadapted to pivot ball members 66 which are carried on operating arms 67.The arms 67 may be integrally formed and are attached to a shaft 68.member 69 which is supported, as indicated at 71, at some suitable placein the fuselage, permits certain side play to the shaft 58 and a largeup and -down movement of the shaft 68. The side play, however, is notgreat.

The shaft 68 is coupled to a shaft 72 through a gimbal joint connection73 which allows motion in all planes. The shaft 72 is journaled insupports 74 which are supported at some convenient place` near the floorofthe fuselage.

The control stick 75 is pivoted at 76 to the shaft 72. The control stick75 is provided at its lower end with a U-shaped support member 77through which the pivot 76 passes. The pivot 76 passes through anaperture in the shaft 72. The U- shaped support 77 permits forward andbackward movement of the control stick 75 by the pilot without affectingthe ailerons.

Upon lateral motion of the control stick 75 the motion of the crank arms61 causes the shafts 58 to rotate in opposite directions to raise or Anelongated link lower the ailerons 50 to give desired rollingI It will beapparent from. an inspection of the linkages and force transmittingmembers that the ailerons 50 may seek a position of balance with theforces of the airstream passing over them when not under active controlof the pilot through lateral motion of the .control stick 75.A Let usassume that the plane is flying in such a position that the forces ofthe airstream tend to raise the trailing edges of the ailerons 50. Thiswill create compression forces in the rods 55which will cause l suchrotation of the shafts 58 as to move the rods 64 downwardly. Because ofthe ball and socket connections of therods 64 to the cranks 61 and tothe arms 67, the effect of theupward nfotion of the trailing edges ofthe., ailerons 50 is to lower" the arms 67 carrying with them the shaft68. The

cof

motions of the parts freely permit this and the downward movement of theshaft 68, because of *the gimbal joint connection at 63, does not in anyway interfere with the immovability of the shaft 72, nor cause anybinding of any of the parts.

On the contrary, upon motion of the control stick in a lateraldirection, the ailerons may be differentially operated to give desirablerolling moments'.

A similar phenomenon occurs when the forces of the airstream passingover the ailerons tend to lower the trailing edge of the ailerons, butin such case the arms 67 are raised, raising with them the end of shaft68. The link 69, in either direction of movement of the shaft 68, tendsto prevent undue lateral movement of the shaft 68 but per.

mits the vertical ing or friction.

In Figure 1.0 I have shown a floating aileron construction in which thefloating aileron is pivoted at a point substantially two-thirds of anaileron chord above the upper surface of the wing. This aileron hasapproximately two-thirds of its chord projecting beyond the trailingedge of the wing.

In Figure l1 I have shown a floating aileron construction in which theleading edge of the movement without undue bindaileron liessubstantially one aileron chord to the rear of the trailing edge of thewing, and in which the pivot point of the aileron is approximately onehalf an aileron chord above the upper surface of the wing.

Figure 12 shows which the floating Wing at a distance of approximatelytwo aileron chords therefrom, and has approximately half its chordprojecting beyond the trailing edge of the wing.

In Figure 13 the floating aileron is pivoted approximately one aileronchord above the upper surface of the wing and has approximately half itschord length projecting behind the trailing edge of the wing.

In Figure 14 I have shown a floating aileron located approximately halfan aileron chord above the upper wing surface. Its leading edge isapproximately two aileron chords in front of the trailing edge of thewing.

The locations of the floating aileron are supposed to be similar to thelocations of the common type of aileron shown and described inconnection with Figures l to 8, inclusive, and what has been saidconcerning the locations of the ailerons shown in Figures 1 to 8inclusive, with respect to their location being substantially within thedownilow, is applicable here. The advantages of location, preferablelimits of position and another possible location in 'other factors aresubstantially the same for both types of aileron. 'I'here are, ofcourse, inherent 'advantages in floating aileron constructions which arenot present in the form shown in Figures 1 to 8 inclusive, and which arepresent in the form shown in Figures 9 to 14 inclusive.

'I'he floating aileron construction permits the ailerons to seek aposition of equilibrium with the forces of the airstream passing overtheir surfaces which presents certain inherent advantages in acuteangles of attack. rIhese advantages are additional to the advantages ofthe aileron locations which have been previously set forth in somedetail.

It is particularly at high angles of attack that the floating aileron isdesirable. At high angles of attack ordinary ailerons are in suchposition as to cause them to be delayed in producing the aileron ispivoted above the desired effect. When the ailerons, however, as in thecase of this floating aileron construction, can assume a position ofbalance with the airstream around them, they are in a position toeflciently operate in response to the pilots control.

While I have shown and described the preferred embodiment of myinvention, I wish it to be understood that I do not conne myself to theprecise details of construction herein set forth, by way ofillustration,` as it is apparent that many changes and variations may bemade therein, by those skilled in the art, without departing from thespirit of the invention, or exceeding the scope of the appended claims.

I claim:-

1. An airplane construction comprising an airffoil having a fluiddownflow region in flight, an aileron so positioned above and withrespect thereto as to have a substantial portion thereof in the downflowover the upper surface cf the airfoil to affect the lift of the airfoilover a substantial portion of its surface to increase the lift of theairfoil on lowering the trailing edge of the aileron; or decrease thelift of the airfoil on raising the trailing edge of the aileron.

2. An airplane construction comprising wings having a fluid downilowregion in night, ailerons so positioned above and with respect theretoas to have a substantial portion thereof in the downflow over the uppersurface of the wings to inl;

crease the downflow of the combination of one wing and its aileron onthe side to be raised and to decrease the velocity of the air flow 'overthe upper surface of the opposite side, thereby producing a` rotationabout the fore and aft axis of the airplane.

3. An airplane construction comprising wings having a fluid downflowregion in flight and ailerons so positioned above and with respectthereto as to lie at least partially in the downflow and l alfect thelift of each wing over a substantial portion of its surface by directlyaffecting its downflow, each aileron having its leading edge fromapproximately two aileron chords in front of the trailing edge of a wingto one aileron chord behind the trailing edge of the Wing and having-its pivot located above the upper wing surface a distance of fromapproximately one-third of an oileron chord to two aileron chords.

4. An airplane construction comprising wings having a fluid downflowregion in flight and ailerons so' positioned above and with respectthereto as to lie at least partially in the downflow and affect the liftof each wing over a substantial portion of its surface by directlyaffecting its n downflow, each aileron having its leading edge fromapproximately two aileron chords in front of the trailing edge of a wingto one aileron chord behind the trailing edge of the wing and locatedsufciently close`to the upper surface lof to affect the flow around thewing.

5. An airplaneconstruction comprising wings having` a `lluid downflowregion in flight and the Wing ric ailerons having a substantial portionof their area in the downilow over the wings and so positioned above andwith respect thereto as to affect the lift of each wing over asubstantial portion of its surface, each aileron having its pivotlocated above the upper wing surface a distance of from one-third of anaileron chord to two aileron chords, and having such a fore and aftlocation as to affect the flow around the wing.

6. An airplane construction comprising Wings having a iluid downflowregion in :flight and ailerons so positioned above and with respect ithereto as to lie at least partially in the downilow lli dll

and affect the lift of each wing over a substantial portion of itssurface, said ailerons being located above the wings and in the vicinityof the rear of the Wings and affecting directly the downilow over thewings, the axis of pivoting of said ailerons being substantiallyperpendicular to the line of Hight.

7. An airplane construction comprising wings having a fluid downflowregion in flight and ailerons so positionedabove and with respectthereto as to aect the lift of each wing over a substantial portion ofits surface, each aileron having its leading edge approximately twoaileron chords in front of the trailing edge of a wing and having itspivot located above the upper surface of the wing a distance ofapproximately two aileron chords and directly `affecting the downflowover the wings by having at least a portion of its surface in saiddownow.

ll. An airplane construction comprising wings having a fluid downflowregion in flight and ailerons so positioned above and with respectthereto as to anect the lift of each wing over a substantial portion ofits surface, each aileron having its leading edge approximately oneaileron chord behind the trailing edge of a wing, and having its pivotlocated above the upper wing surface a distance of approximately twoaileron chords; each aileron being at least partially in the downflow.

9. an airplane construction comprising wings having a fluid downowregion in :Hight and ailelill lill

'lil

rons so positioned above and with respect thereto as to lie at least inpart in the downflow and aect the lift of each wing over a substantialportion of itsv surface, each aileron having its leading edgeapproximately two aileron chords in front of the trailing edge of a wingand having its pivot located above the upper wing surface a distance ofapproximately one-third of an aileron chord and directly affecting thedownflow over its wing.

lll. in airplane construction comprising wings having a fluid downflowregion in flight and'ailerons so positioned above and with respectthereto as to affect the lift of each wing over a substantial portion ofits surface, each aileron having its leading edge approximately twoaileron chords in front of the trailing edge of a wing and having itspivot located above the upper wing surface a distance of approximatelyone aileron chord and having a substantial portion of its area withinthe downllow over its wing.

ll. An airplane construction comprising wings having a fluid downflowregion in flight and ailerons so positioned above and with respectthereto as to affect the lift of each wing over a substantial portion ofits surface, each aileron having a substantial portion of its surfacelying in the downflow over its wing, and having'its leading edgeapproximately. two aileron chords in front of the trailing edge of aWing and having its pivot located above the upper wing surface adistance such thatthe aileron will aneet the flow around the wing.

l2; An airplane construction comprising Wings having a fluid downflowregion in flight and ailerons so positioned above and with respectthereto as to affect the lift of each wing over a substantial po'rtionof its surface, each aileron having its pivot substantially directlyabove the trailing edge of the wing and located approximately half anaileron chord distant therefrom, and each aileron lying substantially inthe downflow.

13. An airplane construction comprising wings having a fluid downflowregion in flight and ailefons so positioned above and with respectthereto as to aect the lift of each wing over a substantial portion ofits surface, each aileron having its pivot substantially directly abovethe trailing edge of the wing and located approximately an aileron chorddistant therefrom, and each aileron lying substantially in the downflow.

14. An airplane construction comprising wings havinga fluid downflowregion in night and ailerons so positioned above and with respectthereto as to affect the lift of each wing over a substantial portion ofits surface, each aileron having its i pivot substantially directlyabove the trailing edge of the wing and located approximately twoaileron chords distant therefrom, and each aileron lying substantiallyin the downflow.

l5. An airplane construction comprising wings having a fluid downflowregion in flight and ailerons so positioned above and with respectthereto as to. affect the lift of each wing over a substantial portionof its surface, each aileron having its leading edge approximately oneaileron chord in front of the trailing edge of a wing and having itspivot located above the upper wing surface approximately an aileronchord distant therefrom, and each aileron lying substantially in thedownfiow.

16. An airplane construction comprising Wings having a fluid downilowregion in flight and ailerons so positioned above and with respectthereto as to affect the lift of each wing over a substantial portion ofits surface, each aileron having its leading edge substantially directlyabove the trailing edge of a wing and having its pivot locatedapproximately half an aileron chord above the upper wing surface at itstrailing edge, and having at least a portion of its surface in thedownllow.

17. An airplane construction comprising wings having a fluid downflowregion in flight and ailerons so positioned above and with respectthereto as to affect the lift of each wingover a substantial portion ofits surface, each aileron having `its leading edge substantiallydirectly above the trailing edge of a wing and having its pivot locatedat approximately one aileron chord vabove the upper wing surface at itstrailing edge,

and having at least a portion of its surface in the downow.

' 18. An airplane construction comprising wings having a fluid downflowregion in flight and ailerons so positioned above and with respect vthereto as to affect the lift of each wing over a substantial portion ofits surface, each aileron having its leading edge substantially directlyabove the trailing edge of a wing and having its pivot located atapproximately two aileron chords distant from the upper wing surface atthe trailing edge, and having at least a portion of its surface in thedownfiow.

19. An airplane construction comprising wings having a fluid downflowregion in flight and ailerons so positioned above and with respectthereto as to affect the lift of each wing over a substantial portion cfits surface, each aileron having its trailing edge substantially in linewith `the trailing edge of the wing and having its pivot located abovethe upper wing surface approximately half an aileron chord distanttherefrom, and having at least a portion of its surface in the downow.

20. An airplane construction comprising wings having a fluid downowregion in` flight and ailerons so positioned above and with respectthereto as to affect the lift of each wing over a substantial portion ofits surface, each aileron having its trailing edge substantially in linewith the trailing edge of the wing and having its pivot located abovethe upper wing surface approximately one aileron chord distanttherefrom, and having at least a portion of its surface in the downnow.

21. An airplane construction comprising wings .having a nuid downnowregion in night and ailerons so'positioned above and with respectthereto as to affect the lift of each wing over a substantial portion ofits surface, each aileron having its trailing edge substantially in linewith the trailing edge of the wing and having its pivot located abovethe upper wing surface approximately two aileron chords distanttherefrom, and having at least a portion of its surface in the downnow.

22. An airplane construction comprising wings having a nuid downnowregion in night and ailerons so positioned above and with respectthereto as to anect the lift of each wing over a substantial portion ofits surface, each aileron having its trailing edge substantially in linewith the trailing edge of the wing and having its pivot located abovethe upper Wing Surface at such a distance that the now around the wingis materially affected both positively and negatively by angularmovement of the aileron, and having at least a. portion of its surfacein the downnow.

23. An airplane construction comprising wings having a fluid downnowregion in night and separate detached ailerons located substantially inthe downnow over the wings and so relatedto the Wings as to affect thenow over a sucient area of the Wings that there is produced a usable andpractical rolling moment in addition to the rolling moment produced bythe airfoil sections of the ailerons.

24. A noating aileron construction comprising an airfoil having a nuiddownnow region in night, a noating aileron so positioned above and withrespect thereto as to anect the now around the airfoil to give bothpositive and negative lift effect on said airfoil, depending uponangular movement of the aileron, said aileron being locatedsubstantially in the downnow over the airfoil.

25. A floating aileron construction comprising wings having a nuiddownnow region in night, and noating separate detached ailerons sorelated to the wings as to an`ect the now over a sucient area of theWings that there is produced a usable and practical rolling moment inaddition to the rolling moment produced by the airfoil sections of theailerons themselves, said ailerons having a substantial portion of theirarea in the downnow over the wings.

26. A floating aileron construction comprising wings having a nuiddownnow region in night, and separate detached ailerons so positionedabove and with respect thereto as to anect the lift of each wing over asubstantial portion of its surface, each noating aileron lying withinthe downnow over its wing and having its leading edge from approximatelytwo aileron chords in front of the" edge of the wing to one aileronchord behind the trailing edge of the wing and located sufficientlyclose to the upper surface of the wing to anect the now around the wing.

27. A noating aileron construction comprising wings having a nuiddownnow region in night,

and floating ailerons so positioned above and with respect thereto as toalect the 'lift of each wing over a substantialportion of its surface,each aileron having its leading edge from approximately two aileronchords in front of the trailing edge of a wing to one aileron chordbehind the trailing edge of the wing and having its pivot located abovethe upper wing surface a distance of from approximately one-third of anaileron chord to two aileron chords, andlying in the downnow.

28. A noating aileron construction comprising' wings having a nuiddownnow region in night, and noating ailerons so positioned above andwith respect thereto as to affect the lift of each Wing over asubstantial portion of its surface, said ailerons being located abovethe wings and in the vicinity of the rear of the wings, and lyingsubstantially in the downnow.

29. In the combination of an airfoil, having a nuid downnow region innight, and aileron, an aileron of the relatively log narrow type sopositioned as to be in and directly innuencethe downnow over arelatively large area ofthe airfoil, and control means for the aileronadapted to give a lesser motion to the trailing edge of the aileron inthe down direction for a given initial movement by the pilot than in theupward direc-I tion, whereby the liftl of the airfoil is largelyan'ected by movement of the aileron to give practical and usable rollingmoments due to change in the lift of the airfoil itself, asdistinguished from the rolling moment produced by the airfoil section ofthe aileron.

30. In the combination of an airfoil, having a nuid downnow region innight, and aileron, a floating aileron of the relatively long narrowtype so positioned as to be in and directly innuence the downnow over arelatively large area of the airfoil and adapted to seek a position ofbalance with the forces o the airstream passing its surface, and controlmeans for the aileron adapted to give a lesser motion to the trailingedge of the aileron in the down direction for a given initial movementby the pilot than in the upward direction, whereby the lift of theairfoil is largely ail'ected by movement of the aileron to givepractical and usable rolling moments due to change in the lift of theairoil itself, as distinguished from the rolling moment produced by theairfoil section of the aileron.

31. In an airplane, wings having a nuid downnow region in night, anaileron for each wing located above the wing and having a substantialportion of its area located in the downnow over its wing, means tooperate the ailerons to lower the trailing edge of one while thetrailing edge of the other aileron is raised, the trailing edge of theraised aileron having a greater motion than the trailing edge of thelower aileron whereby practical and usable rolling moments are generatedby increase in the lift of the wing on which the trailing edge of theaileron is lowered, which are additive to the rolling moments producedby the airfoil section of the aileron itself on that wing, and the liftof the `wing carrying the aileron whose trailing edge'is raised islowered over its normal performance to such an extent as to createpractical and usable rolling moments tending to lower that wing becauseof its loss in lift, which rolling moments are in addition to therolling moments tending to lower the wing which arise from the airfoilsection of the aileron located on that wing.

32. In an airplane, Wings, having a fluid downlill@ iiow region inflight, a floating aileron for each wing located above the wing andhaving a substantial portion of its area located in the downiiow overits wing adapted to seek a position of balance with the forces of theairstream passing its surface, means to operate the floating ailerons tolower the trailing edge oi one while the trailing edge of the other israised, the trailing edge of the raised aileron having a greater motionthan the trailing edge of the lowered aileron whereby practical andusable rolling moments are generated by increase in the lift of the wingon which the trailing edge of the aileron is lowered, which are additiveto the rolling moments produced by, the airfoil section of the aileronitself on that wing, and the lift of the wing carrying the aileron whosetrailing edge is raised is lowered over its normal performance to suchan extent as to create practical and usable rolling moments tending tolower that wing because of its loss in lift, which rolling moments arein addition to the rolling moments tending to lower the wing which arisefrom the airfoil section of the aileron located on that wing.

33. In an aircraft, an airfoil having a trailing edge and having a iiuiddownflow region in flight, an aileron carried by said aircraft andpositioned spaced above and substantially rearwardly of the trailingedge of said airfoil and substantially in the downflow; and means tocontrol said aileron.

34. An airplane construction comprising an airfoil having a iiuiddownflow region in flight, an aileronso positioned above and withrespect thereto as to have a substantial portion of its` area in thedownflow to affect the iiow around the airfoil to give both positive andnegative lift eiiect on said airfoil, depending respectively upon downand up movement of the aileron. 35. An airplane construction comprisingwings having a uid downflow region in flight, ailerons so positionedabove and with respect thereto as to have a substantial portion of itsarea in the downiiow to increase the downflow of the wing to be raisedby lowering the trailing edge of an aileron and t0 decrease the velocityof the airflow over` the upper surface of the wing to be lowered byraising the trailing edge of an aileron, thereby producing a rotationabout `the fore and aft axis of the airplane.

36. An. airplane construction comprising airfols having iiuid downflowregions in flight,

iioating ailerons .adapted to iioat together and so positioned above andwith respect to the airfoils as to have a substantial portion of theirarea in the downiiow to affect the flow around each airfoil to give bothpositive and negative lift effect on said airfoil, ldepending upon upand down movements of the ailerons.

37. A iioating aileron construction comprising wings having a iiuiddownflow region inpfiight, ailerons adapted to iloat together and sopositioned above and with respect to the wings as to affect the `lift ofeach wing over a substantial portion of its surface, said ailerons beinglocated above the wings and in the vicinity of the rear of the wings andlying substantially in the downflow.

EDWARD F. ZAPARKA.

